A free-trade agreement between the U.S. and oil-rich Oman took effect on Jan. 1, eliminating tariff barriers on all consumer and industrial products, including chemicals. The trade pact also provides strong protections for U.S. businesses with investments in Oman, such as Dow and Occidental. "We have worked closely with the government of Oman to ensure that the obligations and responsibilities of each party under the agreement have been met," U.S. Trade Representative Susan C. Schwab . . .